00:01
So we know that the number of people that they polled was 1 ,002, and that they found that of those people, 701 people voted, and they said from the polling records, they know that this is what the percent was.
00:17
And so we can use a normal approximation since n times p and n times 1 minus p are both greater than are equal to 5.
00:26
And when we calculate n times p we get 611 .22.
00:33
And when we calculate the standard deviation, we get n times p times 1 minus p.
00:40
So multiply that answer by 0 .39 and square root it.
00:44
And we get that that standard deviation looks like it is about 15 .39.
00:50
And we want to find in part a what the likelihood is of having 701 or more people who voted.
00:59
And let's use our continuity correction to make this just a tad bit more accurate.
01:06
And then we can convert that to a z value since we know we have an approximate normal distribution...